1. Field of the Invention
The invention generally relates to devices of micro-electro-mechanical systems, and, particularly, to a micro-electro-mechanical pressure sensor.
2. Discussion of Related Art
A micro-electro-mechanical pressure sensor generally includes a sensing part and an application specific integrated circuit (ASIC) part. The sensing part has a vibrating membrane, which vibrates to sound. However, a voltage-loading capability of the sensing part is very small. Thus, the sensing part usually connects with an amplifier, which is used to provide high resistance input and low noise. This makes circuits of the micro-electro-mechanical (i.e., MEM) pressure sensor complicated, thereby adding to the cost thereof.
One prerequisite for this vibrating membrane is that it be as sensitive as possible. One useful method is to improve a compliance degree of the vibrating membrane. Carbon nanotubes have very good mechanical properties and piezoresistive characteristics, especially in thin films embedded with arrays of such carbon nanotubes, and thin films of this nature are capable of being very thin. As such, the compliance degree of such a thin film is particularly suited for forming vibrating membranes. But so far, carbon nanotubes have not been exploited for use in micro-electro-mechanical pressure sensors.
What is needed, therefore, is a micro-electro-mechanical pressure sensor, which has a vibrating membrane containing carbon nanotube structures.